class Solution {
public:
    double myPow(double x, int n) {
        return n < 0 ? 1.0 / pow(x, -(long long)n) : pow(x, n);
    }

    double pow(double x, long long n)
    {
        if (n == 0) return 1;
        double tmp = pow(x, n / 2);
        return n % 2 == 0 ? tmp * tmp : tmp * tmp * x;
    }
};